Hybrid vehicle control device

Abstract

The purpose of the present invention is to provide a control device for a hybrid vehicle with which it is possible to quickly switch from a stationary power generation mode to reverse travel. The control device for a hybrid vehicle comprises: driving wheels; an engine, which is an internal combustion engine; an electric motor that generates motive power to be output to the driving wheels; a transmission positioned on a motive power transmission path between the electric motor and the drive wheels; and a clutch capable of disconnecting the motive power transmission path between the engine and the electric motor. The control device also comprises a controller capable of switching the operation mode of the hybrid vehicle among a stationary electric power generation mode in which electric power is generated while the vehicle is stationary by sending motive power from the engine to the electric motor, a first reverse travel mode in which the vehicle travels in reverse due to the motive power from the engine, and a second reverse travel mode in which the vehicle travels in reverse due to the motive power from the electric motor. The controller switches the operation mode to the second reverse travel mode when there has been a request to switch from the stationary electric power generation mode to the second reverse travel mode.

Description

[Technical Field]

[0001] The present invention relates to a control device for a hybrid vehicle. [Background technology]

[0002] Patent Document 1 shows a hybrid vehicle that is capable of causing an electric motor to generate electricity using the power of the engine while the vehicle is stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-284206 Summary of the Invention [Problem to be solved by the invention]

[0004] Hybrid vehicles have an electric motor arrangement known as the P2 arrangement. The P2 arrangement means that a transmission is located on the power transmission path between the electric motor and the drive wheels, and the power transmission path between the electric motor and the engine can be disconnected by a clutch. Hybrid vehicles that use the P2 arrangement have a problem in that it takes a long time to switch the states of multiple clutches when switching from a stationary power generation mode, in which power is generated using engine power while the vehicle is stopped, to an operating mode in which reverse driving is performed using engine power.

[0005] An object of the present invention is to provide a control device for a hybrid vehicle that can quickly switch from a stationary power generation mode to reverse driving. [Means for solving the problem]

[0006] A control device for a hybrid vehicle according to the present invention is a control device mounted on a hybrid vehicle including drive wheels, an engine which is an internal combustion engine, an electric motor which generates power output to the drive wheels, a transmission located on a power transmission path between the electric motor and the drive wheels, and a clutch which can disconnect the power transmission path between the engine and the electric motor, and is equipped with a controller which can switch the operation mode of the hybrid vehicle among a stationary power generation mode in which power is generated while the hybrid vehicle is stationary by sending power from the engine to the electric motor, a first reverse running mode in which the hybrid vehicle runs in reverse using power from the engine, and a second reverse running mode in which the hybrid vehicle runs in reverse using power from the electric motor, and the controller switches the operation mode to the second reverse running mode when there is a request to switch from the stationary power generation mode to reverse running. When there is a request to switch from an operation mode other than the stationary vehicle power generation mode to reverse driving, the operation mode is switched to the first reverse driving mode. It is characterized by the following. [Effects of the Invention]

[0007] According to the present invention, when there is a request to switch from the stationary vehicle power generation mode to reverse driving, the vehicle switches to the second reverse driving mode, which uses the power of the electric motor to drive in reverse. This switching requires less time to change the clutch state than switching to the first reverse driving mode, which uses the power of the engine to drive in reverse. Therefore, the vehicle can quickly switch from the stationary vehicle power generation mode to reverse driving. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a hybrid vehicle and a control device according to a first embodiment of the present invention. [Figure 2] 5A and 5B are diagrams illustrating the state of the clutch in a first reverse traveling mode. [Figure 3] 10A and 10B are diagrams illustrating the state of the clutch in a second reverse traveling mode. [Figure 4] 10A and 10B are diagrams illustrating the state of the clutch in a stationary power generation mode. [Figure 5] 10 is a flowchart showing a mode switching process executed by a controller. [Figure 6] FIG. 10 is a block diagram showing a hybrid vehicle and a control device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. In this specification, a state in which a clutch transmits power is referred to as an engaged clutch, and a state in which a clutch does not transmit power is referred to as a disengaged clutch.

[0010] (Embodiment 1) FIG. 1 is a block diagram showing a hybrid vehicle and a control device according to a first embodiment of the present invention. The hybrid vehicle 1 according to the first embodiment includes drive wheels 2, an engine 4 which is an internal combustion engine, an accessory 3 for driving the engine 4, an electric motor 6 which generates power output to the drive wheels 2, and an inverter 16 which drives the electric motor 6. The hybrid vehicle 1 further includes a battery 17 which stores the running power and regenerative power of the electric motor 6, and a transmission 8 which is located on a power transmission path between the electric motor 6 and the drive wheels 2. The hybrid vehicle 1 further includes a reverse gear mechanism 10 which can reverse the power of the engine 4, a forward rotation clutch C1 which transmits the power of the engine 4 to a subsequent stage while maintaining forward rotation, and a reverse clutch C2 which transmits the power of the engine 4 via the reverse action of the reverse gear mechanism 10. The hybrid vehicle 1 further includes an output clutch C3 which can cut off the transmission of power to the drive wheels 2 regardless of the operation of the engine 4 and the electric motor 6. Furthermore, the hybrid vehicle 1 may include a torque converter 12 and a latch-up clutch C0 between the engine 4 and the reverse gear mechanism 10, and one or more gear mechanisms 14a, 14b located in the power transmission path. The gear mechanism 14b may include a differential gear.

[0011] The transmission 8 is a CVT (Continuously Variable Transmission). The transmission 8 may be a transmission of another type, such as a stepped transmission.

[0012] The power transmission path from the engine 4 to the drive wheels 2 includes, in this order, a torque converter 12 combined with a latch-up clutch C0, a reverse gear mechanism 10 combined with a forward clutch C1 and a reverse clutch C2, a transmission 8, a gear mechanism 14a, an output clutch C3, and a gear mechanism 14b.

[0013] The power transmission path from the electric motor 6 to the drive wheels 2 includes the transmission 8, the gear mechanism 14a, the output clutch C3, and the gear mechanism 14b in this order.

[0014] The power transmission path from the engine 4 to the electric motor 6 includes, in this order, a torque converter 12 combined with a latch-up clutch C0, and a reverse gear mechanism 10 combined with a forward clutch C1 and a reverse clutch C2. The forward clutch C1 and the reverse clutch C2 also function as clutches that can disconnect the power transmission path between the engine 4 and the electric motor 6. In other words, when both the forward clutch C1 and the reverse clutch C2 are released, no power is transmitted from the engine 4 to the electric motor 6.

[0015] The hybrid vehicle 1 further includes a clutch switching device 18 that switches the state of the clutch. The clutch switching device 18 may include a hydraulic pump 18a that generates hydraulic pressure and a control valve 18b that sends the hydraulic pressure to the clutch to be controlled, and may be configured to switch the clutch using hydraulic pressure. In Figures 1 to 4, hydraulic pressure is indicated by dashed arrows. The clutches to be controlled by the clutch switching device 18 include at least a forward clutch C1, a reverse clutch C2, and an output clutch C3. The clutches to be controlled may further include a latch-up clutch C0.

[0016] When switching a clutch from released to engaged, it is necessary to move the moving parts of the clutch in the hydraulic pressure direction, which consumes energy. However, the workload of the hydraulic pump 18a is limited. Therefore, the number of clutches that can be switched from released to engaged at one time is limited. In the first embodiment, the hydraulic pump 18a is set to have the capacity to switch only one clutch from released to engaged at a time. This setting allows the hydraulic pump 18a to be made more compact. With this setting, when two or more of the forward clutch C1, reverse clutch C2, and output clutch C3 are switched from released to engaged, the switching process for each clutch is performed sequentially at staggered times.

[0017] On the other hand, when switching a clutch from engagement to release, the moving parts of the clutch move in the opposite direction to the hydraulic pressure, so less energy is consumed. Therefore, it is possible to switch multiple clutches from engagement to release at once, regardless of the workload of the hydraulic pump 18a. Furthermore, the process of switching one clutch from release to engagement and the process of switching one or more clutches from engagement to release can be performed in parallel.

[0018] Note that clutch switching device 18 may be configured to switch the clutch state using electric power. In this case, too, if the capacity (maximum output) of clutch switching device 18 is lower than the electric power required to simultaneously switch multiple clutches from released to engaged, a situation similar to that described above may occur.

[0019] The hybrid vehicle 1 further includes a driving operation unit 31 for performing driving operations, a shift operation unit 32 that allows selection of a shift range, and an operation unit 33 that switches between various functions. The shift range includes, for example, a drive range for forward driving, a reverse range for reverse driving, and a stopping range (e.g., a parking range) for continuous stopping. The hybrid vehicle 1 also includes a control device 20 that switches the operating mode of the hybrid vehicle 1 based on the selected shift range and the vehicle state.

[0020] The control device 20 includes a controller 21. The controller 21 is configured to include one ECU (Electronic Control Unit) or multiple ECUs that communicate with each other and operate in cooperation. Operation signals from a driving operation unit 31, an operation signal from a shift operation unit 32, and information indicating the vehicle state (such as vehicle speed and the remaining charge of the battery 17) are sent to the controller 21. The controller 21 can drive and control the engine 4 via the auxiliary equipment 3, and can drive and control the electric motor 6 via the inverter 16. Furthermore, the controller 21 can switch the states of multiple clutches (C0 to C3) by controlling a control valve 18b of a clutch switching device 18.

[0021] <Hybrid vehicle operating modes> Fig. 2 is a diagram illustrating the state of the clutch in the first reverse driving mode. Fig. 3 is a diagram illustrating the state of the clutch in the second reverse driving mode. Fig. 4 is a diagram illustrating the state of the clutch in the stationary power generation mode. In Figs. 2 to 4, clutch engagement is indicated by hatching, and power transmission is indicated by thick arrows.

[0022] The operating modes of the hybrid vehicle 1 include at least a drive mode in which the vehicle travels forward, a reverse mode in which the vehicle travels in reverse, a stop mode in which no power is generated, and a stop power generation mode in which power is generated while the vehicle is stopped. Here, "stopped" means a continuous stop, as opposed to a temporary stop or a stop while waiting at a traffic light, and may also be called parking.

[0023] The operation mode of the hybrid vehicle 1 shifts to a drive driving mode when the drive range is selected in the shift operation unit 32, and shifts to a reverse driving mode when the reverse range is selected in the shift operation unit 32. Furthermore, the operation mode shifts to a stop mode or a stop power generation mode when the stop range is selected in the shift operation unit 32.

[0024] The drive mode includes a drive mode in which only the power of the electric motor 6 is used, and a drive mode in which the power of the engine 4 is used.

[0025] In the drive mode using the power of the engine 4, the forward clutch C1 is engaged, the reverse clutch C2 is disengaged, and the output clutch C3 is engaged. In this mode, the latch-up clutch C0 may be controlled to switch between engagement and disengagement depending on the vehicle state. Depending on the states of the clutches, the power of the engine 4 is transmitted to the drive wheels 2 via the torque converter 12, the forward clutch C1, the transmission 8, the gear mechanism 14a, the output clutch C3, and the gear mechanism 14b, thereby realizing forward travel of the hybrid vehicle 1.

[0026] The rotating shaft of the electric motor 6 is connected to the input shaft of the transmission 8. Therefore, in drive mode, which uses the power of the engine 4, the rotating shaft of the electric motor 6 also rotates. In drive mode, the electric motor 6 is operated at zero torque, thereby reducing the load on the electric motor 6. Furthermore, by operating the electric motor 6 in power running mode, the torque of the drive wheels 2 can be increased by the output torque of the electric motor 6. Furthermore, by operating the electric motor 6 in regenerative mode, part of the power of the engine 4 is sent to the electric motor 6 to generate electricity.

[0027] In the drive mode, which uses only the power of the electric motor 6, the forward clutch C1 is disengaged, the reverse clutch C2 is disengaged, and the output clutch C3 is engaged. With these clutch states, the power of the electric motor 6 is transmitted to the drive wheels 2 via the transmission 8, gear mechanism 14a, output clutch C3, and gear mechanism 14b, allowing the hybrid vehicle 1 to travel forward. Furthermore, with both the forward clutch C1 and the reverse clutch C2 disengaged, the power transmission path between the electric motor 6 and the engine 4 is cut off, allowing the engine 4 to be stopped while traveling.

[0028] The reverse travel modes include a first reverse travel mode in which the vehicle travels in reverse using the power of the engine 4, and a second reverse travel mode in which the vehicle travels in reverse using the power of the electric motor 6.

[0029] In the first reverse driving mode, as shown in FIG. 2, the forward clutch C1 is disengaged, the reverse clutch C2 is engaged, and the output clutch C3 is engaged. In this mode, the latch-up clutch C0 may be disengaged. By switching the clutches in this way, the rotation direction of the power of the engine 4 is reversed by the reverse gear mechanism 10. Furthermore, this power is sent to the drive wheels 2 via the transmission 8, gear mechanism 14a, output clutch C3, and gear mechanism 14b, and reverse driving of the hybrid vehicle 1 is realized.

[0030] In the second reverse driving mode, as shown in Fig. 3, the forward clutch C1 is disengaged, the reverse clutch C2 is disengaged, and the output clutch C3 is engaged. By switching the clutches in this way, the electric motor 6 is powered in reverse, and the reverse rotation power is transmitted to the drive wheels 2 via the transmission 8, gear mechanism 14a, output clutch C3, and gear mechanism 14b, thereby realizing reverse driving of the hybrid vehicle 1. By disengaging both the forward clutch C1 and the reverse clutch C2, the power transmission path between the electric motor 6 and the engine 4 is cut off, and interference with the driving of the electric motor 6 by the engine 4 is suppressed.

[0031] In the stop mode in which no power generation is performed, the forward clutch C1 is controlled to be released and the reverse clutch C2 is controlled to be released. In this mode, the output clutch C3 may be controlled to be released or to be engaged. Furthermore, in this mode, a parking lock mechanism (not shown) may operate to prevent the rotation of the drive wheels 2. In this mode, even if the engine 4 is running, the power of the engine 4 is not transmitted to the drive wheels 2. In addition, the electric motor 6 is stopped.

[0032] In the stationary power generation mode in which power is generated while the vehicle is stopped, as shown in FIG. 4, the forward clutch C1 is engaged, the reverse clutch C2 is disengaged, and the output clutch C3 is disengaged. In this mode, the latch-up clutch C0 may be controlled to be engaged. Furthermore, in this mode, a parking lock mechanism (not shown) may operate to prevent the rotation of the drive wheels 2. In this mode, the engine 4 is driven and the electric motor 6 operates in regenerative mode. Through the above control, the power of the engine 4 is sent to the electric motor 6 via the forward clutch C1. On the other hand, the power of the engine 4 is not output to the drive wheels 2. As a result, the hybrid vehicle 1 is stopped and power is generated by the electric motor 6.

[0033] <Mode switching process by the control device> 5 is a flowchart showing the mode switching process executed by the controller 1. The mode switching process is executed repeatedly at all times while the hybrid vehicle 1 is in system operation.

[0034] When the mode switching process is started, the controller 21 acquires the operation state of the operation unit 33 and the operation state of the shift operation unit 32 (step S1), and further acquires information indicating the vehicle state such as the vehicle speed and the remaining charge of the battery 17 (step S2). The operation of the operation unit 33 and the operation of the shift operation unit 32 may be performed by the driver or may be performed under the control of an automatic driving system.

[0035] Then, the controller 21 determines whether the shift range has been switched based on the signal from the shift operation unit 32 among the operation information acquired in step S1 (step S3). If the result shows that the shift range has not been switched, the controller 21 returns the process to step S1 and repeats the process from step S1.

[0036] On the other hand, if the shift range is switched, the controller 21 determines the selected shift range (step S4), and if it is the drive range, executes processing for switching to the drive driving mode (step S5). The processing of step S5 includes processing for controlling the states of the clutches (C0 to C3) by driving the control valve 18b.

[0037] When switching to the drive traveling mode in step S5, the controller 21 may select, depending on the vehicle state, either a drive traveling mode that uses only the power of the electric motor 6 or a drive traveling mode that uses the power of the engine 4. Furthermore, once the mode has been switched to the drive traveling mode, the controller 21 may switch, based on the vehicle state, between the drive traveling mode that uses only the power of the electric motor 6 and the drive traveling mode that uses the power of the engine 4. Furthermore, once the mode has been switched to the drive traveling mode that uses the power of the engine 4, the controller 21 may switch the operation of the electric motor 6 among zero torque operation, power running operation, and regenerative operation, based on the vehicle state.

[0038] If the result of the determination in step S4 is that the stopping range is selected, controller 21 determines whether the conditions for generating electricity while the vehicle is stopped are met based on the information acquired in steps S1 and S2 (step S6). The power generation conditions may include a condition related to the operation state of operation unit 33, a condition related to the remaining charge of battery 17, etc. For example, in step S6, controller 21 may determine that the conditions for generating electricity while the vehicle is stopped are met when operation unit 33 is in an operation state indicating a power generation request and the remaining charge is equal to or less than a threshold.

[0039] If the result of the determination in step S6 is YES, the controller 21 executes a process of switching to a stationary power generation mode (step S7), and if the result is NO, the controller 21 executes a process of switching to a stationary mode in which power generation is not performed (step S8). The processes in steps S7 and S8 include a process of controlling the states of the clutches (C0 to C3) by driving the control valve 18b.

[0040] The process of switching to the stationary power generation mode in step S7 does not necessarily have to be performed based on a change in the shift range. For example, the controller 21 may perform the process of switching to the stationary power generation mode when the power generation condition is met even if the shift range is not changed during the stationary mode in which power generation is not performed.

[0041] If the result of the determination in step S4 is that the reverse range is selected, the controller 21 determines whether the state of the hybrid vehicle 1 selected at that time is the stationary power generation mode (step S9). The stationary power generation mode determined here may be a state in which the engine 4 is actually driven and the electric motor 6 is generating electricity, or a state in which the driving of the engine 4 and the generation of electricity by the electric motor 6 are stopped (for example, stopped due to completion of charging). The stationary power generation mode determined in step S9 means that the clutches (C0 to C3) are in the stationary power generation mode.

[0042] If the result of the determination in step S9 is YES, the controller 21 executes a process of switching to the second reverse traveling mode (step S10). On the other hand, if the result of the determination in step S9 is NO, the controller 21 executes a process of switching to the first reverse traveling mode (step S11). The processes in steps S10 and S11 include a process of controlling the states of the clutches (C0 to C3) by driving the control valve 18b.

[0043] In the determination process of step S9, if the state of the hybrid vehicle 1 at that time is the stationary power generation mode, the controller 21 branches the process to step S10 regardless of whether the engine 4 is running or stopped. That is, even if the engine 4 is running, the controller 21 selects switching to the second reverse traveling mode in which reverse traveling is performed using the power of the electric motor 6.

[0044] In the determination process of step S9, if the state of the hybrid vehicle 1 at that time is the stationary power generation mode, the controller 21 may branch the process to step S10 without checking the remaining charge of the battery 17. Since the previous state was the stationary power generation mode, the remaining charge of the battery 17 is expected to have recovered. Furthermore, reverse driving often ends after a relatively short distance. Therefore, even if the process proceeds to steps S9 and S10 without checking the remaining charge of the battery 17, it is unlikely that driving of the electric motor 6 will be prohibited due to a decrease in the remaining charge of the battery 17, and the hybrid vehicle 1 can continue to drive normally.

[0045] After the processes of steps S5, S7, S8, S10, and S11, the controller 21 returns the process to step S1.

[0046] The determination conditions in step S9 are not limited to the above example. The determination conditions may include exceptional conditions based on various vehicle conditions, external environmental conditions, driver settings, etc., such that the process branches to step S11 even if the immediately preceding state was the stationary vehicle power generation mode. Even in this case, the second reverse driving mode is selected when switching from the stationary vehicle power generation mode to reverse driving under conditions other than the exceptional conditions, and the effects described below can be achieved through this selection. Furthermore, the determination conditions in step S9 are not limited to the above example. They may include other conditions based on various vehicle conditions, external environmental conditions, driver settings, etc., such that the process branches to step S10 even if the immediately preceding state was not the stationary vehicle power generation mode. Therefore, when switching from an operating mode other than the stationary vehicle power generation mode to reverse driving, an operating mode in which reverse driving is performed using the power of the electric motor 6 may be selected depending on various conditions.

[0047] The program for the mode switching process described above is stored in a non-transitory computer readable medium, such as the storage device 22 included in the controller 21. The controller 21 may be configured to read and execute a program stored in a portable non-transitory recording medium. The portable non-transitory recording medium may store the program for the mode switching process described above.

[0048] <Details on switching to reverse driving mode> When switching from the stationary power generation mode to the reverse driving mode in steps S9 and S10 of FIG. 5, the controller 21 automatically selects the second reverse driving mode in which the vehicle is driven in reverse using the power of the electric motor 6 as the mode to switch to.

[0049] When switching to the second reverse driving mode, the clutch that is switched from released to engaged is the output clutch C3, and the clutches that are switched from engaged to released are the latch-up clutch C0 and the forward clutch C1. As described above, the controller 21 can quickly switch multiple clutches from engaged to released. Furthermore, when switching a clutch from released to engaged, the controller 21 takes one switching time per clutch. Because the clutch that is switched from released to engaged in the above switching is the output clutch C3, the controller 21 can quickly switch from the stationary power generation mode to the second reverse driving mode. Therefore, the hybrid vehicle 1 can quickly transition from a stationary state to reverse driving.

[0050] A hypothetical case will be described in which the controller 21 switches from the stationary power generation mode to the first reverse traveling mode. In this switching, the clutches that are switched from released to engaged are the reverse clutch C2 and the output clutch C3, and the clutches that are switched from engaged to released are the latch-up clutch C0 and the forward clutch C1. As described above, the controller 21 can quickly switch multiple clutches from engaged to released. However, when switching two clutches (C2, C3) from released to engaged, the controller 21 executes the switching process sequentially, which requires two switching times. Therefore, switching from the stationary power generation mode to the first reverse traveling mode takes a longer time than switching to the second reverse traveling mode. Therefore, in this case, the driver feels a sluggishness in transitioning from a stationary state to reverse traveling.

[0051] As described above, according to the hybrid vehicle 1 and the control device 20 of the first embodiment, when there is a request to switch from the stationary power generation mode to reverse traveling, the controller 21 switches the operation mode to the second reverse traveling mode. Switching from the stationary power generation mode to the second reverse traveling mode can be accomplished more quickly than switching to the first reverse traveling mode. Therefore, the hybrid vehicle 1 can quickly transition to reverse traveling.

[0052] Furthermore, according to the hybrid vehicle 1 and control device 20 of the first embodiment, when switching from the stationary power generation mode to the second reverse traveling mode, the controller 21 switches to the second reverse traveling mode even if the engine 4 is running. Therefore, even if the engine 4 is running, it is possible to quickly transition to reverse traveling. Since reverse traveling does not generally continue for a long period of time, even if the engine 4 is running in the second reverse traveling mode, the impact on fuel economy is very small.

[0053] Furthermore, according to the hybrid vehicle 1 and control device 20 of the first embodiment, the controller 21 controls the forward clutch C1 to be engaged, the reverse clutch C2 to be disengaged, and the output clutch C3 to be disengaged in the stationary power generation mode. Furthermore, the controller 21 controls the forward clutch C1 to be disengaged, the reverse clutch C2 to be engaged, and the output clutch C3 to be engaged in the first reverse driving mode. Furthermore, the controller 21 controls the forward clutch C1 to be disengaged, the reverse clutch C2 to be disengaged, and the output clutch C3 to be engaged in the second reverse driving mode. When switching from the stationary power generation mode to reverse driving, the controller 21 automatically selects the second reverse driving mode, which requires only one clutch to be switched from released to engaged. Therefore, a quick switch from the power failure power generation mode to reverse driving can be achieved without increasing the number or capacity of the clutch switching devices 18, i.e., without increasing the number of clutches that can be switched from released to engaged at one time. This allows the clutch switching device 18 to be made more compact.

[0054] Furthermore, according to the hybrid vehicle 1 and control device 20 of the first embodiment, the clutch switching device 18 is configured to switch the clutch using hydraulic pressure. In a configuration that switches the clutch using hydraulic pressure, increasing the capacity of the clutch switching device 18 requires significant modification from the previous configuration, which increases the development cost of the hybrid vehicle 1. Therefore, being able to quickly switch from power outage power generation mode to reverse driving without increasing the number or capacity of the clutch switching devices 18 is particularly useful when adopting a clutch switching device 18 that uses hydraulic pressure.

[0055] Furthermore, according to the hybrid vehicle 1 and the control device 20 of the first embodiment, when there is a request to switch to reverse driving from an operating mode other than the stationary power generation mode, the controller 21 can switch the operating mode to the first reverse driving mode. There may be situations where it is preferable to use the power of the engine 4 due to the vehicle state, various other environmental conditions, driver requests, etc. In such situations, the first reverse driving mode is selected when it is possible to switch to reverse driving in a relatively short time, thereby realizing reverse driving suited to the situation.

[0056] (Embodiment 2) 6 is a block diagram showing a hybrid vehicle and a control device according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in part of the power transmission mechanism of the hybrid vehicle 1A and the state of the clutch in each operation mode, but is otherwise similar to the first embodiment. The same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0057] In addition to the power transmission mechanism of embodiment 1, the hybrid vehicle 1A of embodiment 2 includes a direct gear mechanism 15 that can transmit power from the engine 4 or the electric motor 6 to the drive wheels 2 without going through the transmission 8, and a second output clutch C5 that connects the direct gear mechanism 15 to the power transmission path on the power side. The second output clutch C5 may be located on the output shaft of the reverse gear mechanism 10, i.e., the input shaft of the transmission 8, and connects or disconnects this shaft to the direct gear mechanism 15. In embodiment 2, the clutch that connects the output shaft of the transmission 8 and the propulsion shaft of the drive wheels 2 is referred to as a first output clutch C3.

[0058] The hybrid vehicle 1A of the second embodiment further includes two drive wheels 2A and a transfer clutch C6 that transmits power to the propulsion shafts of the drive wheels 2A.

[0059] The controller 21 can switch the states of the multiple clutches (C0 to C3, C5, C6) by controlling the control valve 18b of the clutch switching device 18. In Figure 6, the hydraulic pressure sent from the control valve 18b is indicated by a dashed arrow.

[0060] In the second embodiment, the first output clutch C3 or the second output clutch C5 corresponds to an example of an output clutch according to the present invention. In the second embodiment, the forward clutch C1 and the reverse clutch C2 also function as clutches that can disconnect the power transmission path between the engine 4 and the electric motor 6. In other words, the power transmission path between the engine 4 and the electric motor 6 is disconnected by releasing both the forward clutch C1 and the reverse clutch C2.

[0061] <Operation mode and clutch status> Similar to the first embodiment, the operation modes of the hybrid vehicle 1A include a drive mode, a first reverse mode using the power of the engine 4, a second reverse mode using the power of the electric motor 6, a stationary mode, and a stationary power generation mode. The conditions for switching to each operation mode are similar to those of the first embodiment.

[0062] The following describes the case where power is transmitted to the drive wheels 2 via the direct gear mechanism 15. However, power may also be transmitted to the drive wheels 2 via the transmission 8, and in that case, the second output clutch C5 is controlled to be released, which is the same as in embodiment 1. Whether power is transmitted via the direct gear mechanism 15 or via the transmission 8 can be selected according to the driver's selection operation or the vehicle state.

[0063] The drive mode includes a drive mode in which only the power of the electric motor 6 is used, and a drive mode in which the power of the engine 4 is used.

[0064] In the drive mode using the power of the engine 4, the forward clutch C1 is engaged, the reverse clutch C2 is disengaged, the first output clutch C3 is disengaged, and the second output clutch C5 is engaged. In this mode, the latch-up clutch C0 may be controlled to switch between engagement and disengagement depending on the vehicle state. Depending on the states of the clutches, the power of the engine 4 is transmitted to the drive wheels 2 via the torque converter 12, the forward clutch C1, the second output clutch C5, the direct gear mechanism 15, and the gear mechanisms 14a and 14b, allowing the hybrid vehicle 1 to travel forward.

[0065] In the drive mode, which uses only the power of the electric motor 6, the forward clutch C1 is disengaged, the reverse clutch C2 is disengaged, the first output clutch C3 is disengaged, and the second output clutch C5 is engaged. With these clutch states, the power of the electric motor 6 is transmitted to the drive wheels 2 via the second output clutch C5, direct gear mechanism 15, and gear mechanisms 14a and 14b, allowing the hybrid vehicle 1 to travel forward. Furthermore, with both the forward clutch C1 and the reverse clutch C2 disengaged, the power transmission path between the electric motor 6 and the engine 4 is cut off, allowing the engine 4 to be stopped while the vehicle is traveling.

[0066] In the first reverse driving mode, the forward clutch C1 is disengaged, the reverse clutch C2 is engaged, the first output clutch C3 is disengaged, and the second output clutch C5 is engaged. In this mode, the latch-up clutch C0 may be disengaged. By switching the clutches in this way, the rotation direction of the engine 4 is reversed by the reverse gear mechanism 10, and the power is transmitted to the drive wheels 2 via the second output clutch C5, the direct gear mechanism 15, and the gear mechanisms 14a and 14b, thereby realizing reverse driving of the hybrid vehicle 1.

[0067] In the second reverse traveling mode, the forward clutch C1 is disengaged, the reverse clutch C2 is disengaged, the first output clutch C3 is disengaged, and the second output clutch C5 is engaged. By switching the clutches in this way, the electric motor 6 is powered in reverse, and the reverse rotation power is transmitted to the drive wheels 2 via the second output clutch C5, the direct gear mechanism 15, and the gear mechanisms 14a and 14b, thereby realizing reverse traveling of the hybrid vehicle 1. By disengaging both the forward clutch C1 and the reverse clutch C2, the power transmission path between the electric motor 6 and the engine 4 is cut off, and interference with the driving of the electric motor 6 by the engine 4 is suppressed.

[0068] In a stop mode in which no power generation is performed, the forward clutch C1 is released, the reverse clutch C2 is released, the first output clutch C3 is released, and the second output clutch C5 is engaged. In this mode, the first output clutch C3 may be released, and the second output clutch C5 may be released. Furthermore, in this mode, a parking lock mechanism (not shown) may operate to prevent the rotation of the drive wheels 2. In this mode, even if the engine 4 is running, the power of the engine 4 is not transmitted to the drive wheels 2. In addition, the electric motor 6 is stopped.

[0069] In a stationary power generation mode in which power is generated while the vehicle is stopped, the forward clutch C1 is engaged, the reverse clutch C2 is disengaged, the first output clutch C3 is disengaged, and the second output clutch C5 is disengaged. In this mode, the latch-up clutch C0 may be controlled to be engaged. Furthermore, in this mode, a parking lock mechanism (not shown) may operate to prevent the rotation of the drive wheels 2. In this mode, the engine 4 is driven and the electric motor 6 operates in regenerative mode. Through the above control, the power of the engine 4 is sent to the electric motor 6 via the forward clutch C1. Meanwhile, the power of the engine 4 is not output to the drive wheels 2. As a result, the hybrid vehicle 1 is stopped and power is generated by the electric motor 6.

[0070] The transfer clutch C6 is controlled to be engaged when four-wheel drive is selected, and is controlled to be released when two-wheel drive is selected, depending on the driver's selection or the vehicle state.

[0071] <Mode switching process> The controller 21 of the control device 20 executes the process of switching the operation mode in the same manner as in embodiment 1. Then, similar to embodiment 1, when switching from the stationary power generation mode to reverse traveling, the controller 21 automatically selects switching to the second reverse traveling mode.

[0072] If the vehicle is switched from the stationary power generation mode to the first reverse driving mode, two clutches are switched from released to engaged: the reverse clutch C2 and the second output clutch C5. Therefore, the time required for the switchover includes the time required to switch the clutches twice.

[0073] On the other hand, when the hybrid vehicle 1A is switched from the stationary power generation mode to the second reverse driving mode, only one clutch, the second output clutch C5, is switched from released to engaged. Therefore, the time required for the switch is shortened, and the hybrid vehicle 1A can quickly transition to reverse driving.

[0074] The hybrid vehicle 1A and the control device 20 of the second embodiment also achieve the same effects as those of the first embodiment.

[0075] The above describes various embodiments of the present invention. However, the present invention is not limited to the above embodiments. For example, the gear configuration and clutch configuration shown in the embodiments can be arranged in several patterns without changing the function. In addition, the details shown in the embodiments can be changed as appropriate without departing from the spirit of the invention. [Industrial Applicability]

[0076] The present invention can be used in a control device for a hybrid vehicle. [Explanation of symbols]

[0077] 1. 1A Hybrid vehicle 2, 2A drive wheels 3 Auxiliary equipment 4 Engine 6 electric motor 8-speed 10 Reverse gear mechanism 12 Torque converter C0 Latch-up clutch C1 forward clutch C2 Reverse clutch C3 Output clutch (first output clutch) C5 Second output clutch C6 Transfer Clutch 14a, 14b gear mechanism 15 Direct gear mechanism 16 inverters 17 Battery 18 Clutch switching device 18a Hydraulic Pump 18b Control valve 20 Control device 21 Controller 22 Storage device 31 Driving operation unit 32 Shift operation unit 33 Operation section

Claims

1. A control device mounted on a hybrid vehicle including drive wheels, an internal combustion engine, an electric motor that generates power output to the drive wheels, a transmission located on a power transmission path between the electric motor and the drive wheels, and a clutch that can disconnect the power transmission path between the engine and the electric motor, a controller that can switch the operation mode of the hybrid vehicle among a stationary power generation mode in which power of the engine is sent to the electric motor to generate power while the hybrid vehicle is stationary, a first reverse running mode in which the hybrid vehicle runs in reverse using power from the engine, and a second reverse running mode in which the hybrid vehicle runs in reverse using power from the electric motor; The controller when there is a request to switch from the stationary vehicle power generation mode to reverse traveling, the operation mode is switched to the second reverse traveling mode; A control device for a hybrid vehicle, characterized in that, when there is a request to switch to reverse driving from an operation mode other than the stationary power generation mode, the operation mode is switched to the first reverse driving mode.

2. The controller 2. The control device for a hybrid vehicle according to claim 1, wherein when there is a request to switch from the stationary power generation mode to reverse driving, the operation mode is switched to the second reverse driving mode even if the engine is running.

3. The hybrid vehicle includes a forward rotation clutch that transmits the power of the engine while maintaining forward rotation, a reverse clutch that transmits the power of the engine via a reverse gear mechanism, an output clutch that transmits the power transmitted via the forward rotation clutch or the reverse clutch to the drive wheels, and a clutch switching device that switches the states of the forward rotation clutch, the reverse clutch, and the output clutch, The controller In the stationary power generation mode, the forward clutch is engaged, the reverse clutch is released, and the output clutch is released; When in the first reverse traveling mode, the forward rotation clutch is released. Controlling the reverse clutch to be engaged and the output clutch to be engaged; When in the second reverse traveling mode, the forward rotation clutch is released.

3. The control device for a hybrid vehicle according to claim 1, wherein the reverse clutch is controlled to be released and the output clutch is controlled to be engaged.

4. 4. The control device for a hybrid vehicle according to claim 3, wherein the clutch switching device switches between engagement and release of each of the forward clutch, the reverse clutch, and the output clutch using hydraulic pressure.

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